JP2002160115A - Machine tool, particularly high-speed complex machine tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a better operating method and especially to prevent a high acceleration from causing inaccuracy of machining, in a machine tool, especially a high-speed complex machine tool, for cutting a machined material, especially milling an outline. SOLUTION: A tool 6 is turnably disposed in a receiving unit 8 of which position is adjusted in the main moving direction (X direction) around a rotating shaft 9, and so that its center 14 of gravity is positioned at a rotating point 13 of the turning shaft 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a machine tool for cutting a work material, especially for milling a contour, and more particularly to a high-speed compound machine tool (high-speed machining center). A reciprocating crossbar, a carriage supported by the crossbar and movable in the Y direction in a direction transverse to the crossbar, and the carriage is capable of moving up and down in the Z direction, that is, vertically. And a slider at its lower end provided with a tool.

[0002]

2. Description of the Prior Art In particular, when machining contours in components or workpieces, the larger the machine tool and, in parallel with it, the greater the mass of the moving parts to be accelerated, the more problematic it is. A sudden acceleration occurs. Due to the inertial force of the accelerated mass, the natural deformation of the machine occurs.
The mechanical part is excited at its natural frequency and leads to continuing to vibrate. This results in damage or inaccuracies in the trajectory of the contour of the workpiece to be manufactured or milled. That is, when the crossbar is urged with a large acceleration, the slider is deformed or displaced in the main movement direction. At the end of the acceleration phase, the slider does not immediately return to its starting position, but rather swings off, which is repeated many times as it decayes. To cope with the inaccuracies resulting from the quality of the work material to be machined from this, it is known to input deviations or distortions from the beginning into the machine control as trajectory corrections.

[0003]

In view of this, the object underlying the present invention is to make it possible to use a machine tool of the type mentioned at the beginning in a better way, especially in the case of machining problems caused by large accelerations. Avoid precision.

[0004]

According to the invention, the object is achieved in that a tool is positioned about a rotation axis in a main movement direction and is pivotable on a receiving unit which is preferably formed as a fork head. In addition, the above problem is solved by arranging the center of gravity so as to be located at the rotation point of the turning shaft. As a result, parts of the machine tool with a large mass (such as a crossbar with a carriage) can
It is traveled using only small accelerations of ２2 m / s ² , whereas it is achieved that the small pivot axis achieved very close to the tool performs a motion superimposed on it with little mass. . Here, the measure that the pivot axis of the tool has the pivot point of the pivot axis exactly at the center of mass offers the further advantage of minimizing disturbance forces. This is because no force is added to the slider, and the force is offset rather. In addition, continuous drive can be used for accelerations greater than 1 g. This is because the mass of the receiving unit or fork head to be accelerated is very small. On the other hand, a special drive should be used at comparable high accelerations of all crossbars, since continuous production is not available due to the large mass to be moved.

An advantageous proposal according to the invention takes into account the provision of a weight-balancing device on the slider to be accelerated vertically. The weight balancing device advantageously operates in the opposite direction to the slider movement, each being half the weight of the slider, thereby being achieved by two balancing masses which together have the same mass as the slider. Is done. Therefore, no overturning moment is generated despite the large acceleration to the crossbar which should be realized for the slider in the Z direction or the Z axis without changing. This is because the forces of the masses that are accelerated in opposite directions cancel each other.

The avoidance of dimensional errors caused dynamically by the still large acceleration of the slider in the Z-direction has been assisted according to the invention by the balancing mass engaging the respective drive pinion of the slider. As soon as the slider moves in one direction, the provided pinion without play causes the counterweight to immediately start moving in the opposite direction. To this end, each drive pinion is connected to a motor that is decelerated by a gear device.

[0007] According to an advantageous configuration of the invention, the slider and the balancing mass are weight-balanced by the gas. Due to the complete weight reduction of these components achieved in this way, the effects of gravitational acceleration superimposed on vertical slider acceleration are eliminated. This weight reduction is advantageously achieved, for example, by providing the balancing mass with one gas cylinder each and the slider with two gas cylinders operating in opposite directions and all connected to one another. Achieved. As a result, the air is moved back and forth, so that no additional means are required. When the slider is lowered, the air pushed from the air cylinder is supplied in the opposite direction to the gas cylinder of the balancing mass.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described in more detail with reference to the embodiments illustrated in the drawings.

FIG. 1 shows a cross bar 3 which is movable in a main direction X on a linear guide 2 in a machine tool 1 which is shown substantially only with rough lines. The crossbar 3 supports a carriage 4 movable in the Y direction, that is, the lateral direction with respect to the crossbar 3, and a slider 5 to be vertically moved or accelerated in the Z direction is provided on the carriage 4. Have been. At the lower end of the slider 5, a tool 6, for example, a milling tool, for processing a processing material (not shown), which is fastened and fixed on a machine table 7, is provided. For the sake of clarity, in FIG. 1, when the crossbar 3 is urged with a large acceleration, the deformation state of the slider 5 is emphasized by a dashed-dotted line protruding greatly.

This deformation occurs when the crossbar with a large mass moves with only a small acceleration, and instead, when a superimposed movement is imposed on the tool 6, as shown in FIG. To be avoided. For this purpose, according to this embodiment, the tool 6 is arranged on a tool and receiving unit formed as a forkhead 8. The fork head 8, which is constantly adjusted in the main movement direction X about the axis of rotation 9 according to the bidirectional arrow 10, has a small pivot 11 with a pivoting movement in the direction of the bidirectional arrow 12 with very little mass or low weight.
Can be formed in the immediate vicinity of the tool 6. The tool 6 can thereby be operated without the inaccuracies of the mechanical deformation occurring during the production of the work material to be machined, and can be biased by the superimposed movement. Furthermore, possible disturbance forces are minimized by the fact that the point of rotation 13 of the tool 6 is identical to the mass center of gravity 14, whereby
No force is applied to the slider 5.

Referring to FIG. 4, a work material 1 is obtained by superimposing movements when intentionally reducing the acceleration in the direction of the main axis X (or Y) for various operating positions I to V.
The creation of the contour or step in 5 will be described. At position I, only the crossbar (see FIG. 1) moves in the X direction. When the position II has been reached, i.e., X has moved forward by creating a contour corresponding to the predetermined machine trajectory, the tool 6 via the pivot 9 is subjected to a correction by superposition of the movements. This also occurs at position III. At position IV, it is recognized that after completion of the contour, the tool 6 rotated about the pivot axis 11 has almost regained its X main direction movement. According to V, the correction process has been completed by the superposition of the movements, and there will be a movement course as in I until a subsequent contour machining.

In order to eliminate the gravitational force of the slider 5 to be accelerated vertically, the slider 5 is provided with a weight balancing device 16 according to FIG. This weight balancing device 16
Two balancing masses 1 operating in opposite directions (see inscribed arrows) for the respective direction of movement of the slider 5
7a and 17b. These balancing masses 17a, 1
7b is connected to the slider 5 via pinions 18a, 18b respectively connected to a drive unit (not shown), wherein the pinions 18a, 18b are on the one hand a rack 19 of the slider 5 and on the other hand a fishing Combined mass 17a, 1
7b engages with the rack 20.

The gravitational acceleration superimposed on the vertical acceleration of the slider 5 and the counterweights 17a, 17b is eliminated if these parts are lightened. This is not shown (two for the slider 5 and one for each balancing mass 17a or 17b).
This can be achieved by a gas cylinder. In this device,
The gas cylinders of the slider 5 are balanced mass bodies 17a, 17b.
When operating in the opposite direction for the gas cylinders of this type, no additional measures are required.

[Brief description of the drawings]

FIG. 1 is an overall perspective view of a machine tool having machine parts moved in X, Z, and Y directions.

2 shows, as a detail of FIG. 1, a slider which is moved vertically in the Z-direction, the slider being provided with a tool and receiving unit which is arranged at the bottom and is rotatable and pivotable. ing.

FIG. 3 is a diagram showing an overall view of a weight balancing device attached to the slider according to FIG. 2;

FIG. 4 is an enlarged view showing a state in which a workpiece contour is manufactured at a plurality of operating positions by superimposing the acceleration of a crossbar due to a turning motion of a tool.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Machine tool 2 Linear guide 3 Cross bar 4 Carriage 5 Slider 6 Tool 7 Machine table 8 Fork head 9 Rotating axis 10 Fork head turning direction 11 Turning axis 12 Tool turning direction 13 Tool rotation point 14 Tool mass center of gravity 15 Processing Material 16 Weight balancer 17a Balance mass 17b Balance mass 18a Pinion 18b Pinion 19 rack 20 rack

Claims (6)

[Claims] 1. A machine tool for cutting a work material, in particular for milling contours, in particular a high-speed compound machine tool, comprising a crossbar reciprocally movable in the X direction.
A carriage supported by the crossbar and movable in the Y direction in a lateral direction with respect to the crossbar;
In the machine tool, the carriage (6) can move up and down in the Z direction, that is, vertically, and has a tool at its lower end. The receiving unit (8), the position of which is adjusted in the main movement direction (X direction), is rotatably disposed such that its center of gravity (14) is located at the rotation point (13) of the rotation axis (11). A machine tool characterized by being 2. The machine tool according to claim 1, wherein a fork head is provided as a tool and receiving unit. 3. The machine tool according to claim 1, wherein the slider (5) to be vertically accelerated is provided with a weight balancing device (16). 4. A balancing device (16) which operates in the opposite direction to the slider movement and which has two balancing masses (17a, 17) each having half the weight of the slider (5).
4. The machine tool according to claim 3, comprising b). 5. A balancer (17a, 17b) comprising a drive pinion (18a, 18b) for each of the sliders (5).
The machine tool according to claim 3, wherein the machine tool is engaged with the machine tool. 6. A slider (5) and a balancing mass (17a, 1).
The machine tool according to claim 3, wherein the weight of 7b) is reduced by gas.